1. Field of the Invention
This invention relates to a serial type recording apparatus which is applicable to a recording apparatus in a business machine or a communication instrument such as a copying machine, a facsimile apparatus, a personal computer or an office computer, and in particular to a recording apparatus which can be effectively applied to an ink jet recording apparatus in which a carrier is caused to scan in the direction of a recording column to thereby accomplish recording.
2. Related to Background Art
Among the serial type recording apparatuses, such as ink jet recording apparatuses, wire dot printers and heat transfer printers, proposed before the present invention, there is one in which a recording head is carried on a single carriage and when image recording using different ink is to be effected, the recording head is interchanged with another recording head by a manual operation. However, in such an apparatus, it is not intended that a plurality of recording heads be carried on the carriage to effect color recording. and such apparatus is not constructed so that a plurality of recording heads can be carried on the carriage. In any case, black documents and black printing mode data processing are more often used for printing in a terminal instrument than colored graphics and colored documents.
Instead of the manual operation, it is conceivable to move a carriage carrying a plurality of recording heads thereon serially to thereby enable printing in any color to be accomplished, but this will result in a construction in which an unused recording heads are always moved or continue to be moved in a state capable of recording. Accordingly, in the heretofore known ink jet recording, unused recording heads are subjected to the recovery process or ink is heated, which leads particularly to the waste of time and the waste of electric power. Also, the carriage carries the maximum weight thereon at all times and, therefore, the load for moving the carriage becomes great.
On the other hand, a color ink jet printer carried recording heads for four colors, i.e., Bk (black), Y (yellow), M (magenta) and C (cyan) in parallel on a single carriage and has effected printing by causing the carrier to scan.
However, in the ink jet printer, during black printing, the other printing heads are exposed to the atmosphere, and this causes problems such as clogging and adherence resulting from the desiccation of ink. These problems arise earlier in a recording head being not used than in a recording head being used, and even if the recovery process is carried out, the period during which these problems arise becomes very short. During recovery process, it is usually the practice to return the carriage periodically to its home position even during black printing to thereby effect idle discharge, or to effect suction of ink from the color printing heads even during the closing of the main switch or the suction recovery operation, and this brings about the inconvenience that the recording time is prolonged. Also, by this recovery process, the color inks are wastefully consumed, and this has been uneconomical.
Also, even when high-speed printing is to be effected, it has been necessary to drive the heavy carrier carrying the four recording heads thereon and thus, an expensive and bulky motor for driving the carrier has been necessary.
Even in printing conditions under which black printing can be executed, the absence of other color inks makes printing impossible.
Also, in spite of the execution of printing being possible if the temperature control of only the black head is effected in printing conditions under which black printing can be executed, waste such as effecting the temperature control of the other color heads, for example, warming all the heads so as to assume 35.degree. C. or higher, is unavoidable.
The present invention has been made on the basis of the above-described background art, and more particularly from a point of view which has not heretofore been foreseen.